On Mon, Nov 02, 2020 at 04:15:01PM +0000, Javier Gonzalez wrote: > That said, I don't mind the concept, though I recall Christoph had > concerns about the existing 0-capacity namespace used for invalid > formats, so I'd like to hear more on that if he has some spare time to > comment. Yes, I really don't think 0 sized block devices are the right interface for namespaces we can't access. I think the proper fix is to ensure that we have a character device that allows submitting I/O commands for each namespaces including those where we don't understand the I/O command set or parts of it. That should also really help to have a proper access model for the KV command set. Initially we only need NVME_IOCTL_IO64_CMD, but eventually we'll need some support for async submissions, be that through io_uring or other ways.
